What are the trading hours?

How do I report a trading problem?

What does an ask price mean? And how about a bid price?

What does the side (buy/sell) of orders mean?

Can I go long and short on the same market, at the same time? And can I hedge?

What's the spread? How do I view real-time spreads?

Is there a cap on an open position volume?

Why did my account balance become negative? How do I fix it?

Can I partially close my position?